<scp>KMT2D</scp> links <scp>TGF</scp> ‐β signaling to noncanonical activin pathway and regulates pancreatic cancer cell plasticity
Shuang Lu, Hong Sun Kim, Yubo Cao, Karan Bedi, Lili Zhao, Ishwarya Venkata Narayanan, Brian Magnuson, Yumei Gu, Jing Yang, Zhujun Yi, Sepideh Babaniamansour, Sargis Shameon, Chang Xu, Michelle T. Paulsen, Ping Qiu, Sivakumar Jeyarajan, Mats Ljungman, Dafydd Thomas, Yali Dou, Howard C. Crawford, Marina Pasca di Magliano, Kai Ge, Bo Yang, Jiaqi Shi
Abstract
Although KMT2D, also known as MLL2, is known to play an essential role in development, differentiation, and tumor suppression, its role in pancreatic cancer development is not well understood. Here, we discovered a novel signaling axis mediated by KMT2D, which links TGF-β to the activin A pathway. We found that TGF-β upregulates a microRNA, miR-147b, which in turn leads to post-transcriptional silencing of KMT2D. Loss of KMT2D induces the expression and secretion of activin A, which activates a noncanonical p38 MAPK-mediated pathway to modulate cancer cell plasticity, promote a mesenchymal phenotype, and enhance tumor invasion and metastasis in mice. We observed a decreased KMT2D expression in human primary and metastatic pancreatic cancer. Furthermore, inhibition or knockdown of activin A reversed the protumoral role of KMT2D loss. These findings support a tumor-suppressive role of KMT2D in pancreatic cancer and identify miR-147b and activin A as novel therapeutic targets.